Scutelleridae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

true bugs Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, Cimex, bed bugs, and shield bugs. They ...

. They are commonly known as jewel (stink) bugs or metallic shield bugs due to their often brilliant coloration. With the name based on the Asian genus ''

Scutellera ''Scutellera'' is the type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoolo ...

'', they are also known as shield-backed bugs due to the enlargement of the thoracic scutellum into a continuous shield over the

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

and wings. This latter characteristic distinguishes them from most other families within

Heteroptera The Heteroptera are a group of about 40,000 species of insects in the order Hemiptera. They are sometimes called "true bugs", though that name more commonly refers to the Hemiptera as a whole. "Typical bugs" might be used as a more unequivocal al ...

, and may lead to misidentification as a

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

rather than a bug. These insects use their piercing-sucking mouthparts to feed on plant juices from a variety of different species, including some commercial crops. Closely related to

stink bug Stink bug may refer to: * Any insect in the true bug ( hemipteran) family Pentatomidae, generally called shield bugs or stink bugs **''Halyomorpha halys'', or brown marmorated stink bug **'' Chinavia hilaris'', or green stink bug * Any insect in ...

s, they may also produce an offensive odour when disturbed. There are around 450

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

worldwide.

Description

Jewel bugs are small to medium-sized oval-shaped bugs with a body length averaging at . They can easily be distinguished from stink bugs (

Pentatomidae Pentatomidae is a family of insects belonging to the order Hemiptera, generally called shield bugs or stink bugs. Pentatomidae is the largest family in the superfamily Pentatomoidea, and contains around 900 genera and over 4700 species.Robert G ...

) because the shield-like enlarged last section of their

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

(known as the scutellum,

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for "little shield") completely covers the

and the wings. Despite their resemblance to beetles, jewel bugs are

hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from ...

ns or true bugs. The scutellum is an extension of the thorax, unlike the

elytra An elytron (; ; : elytra, ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometime ...

of beetles which are hardened

forewing Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwi ...

s. As such, jewel bugs have four membranous wings underneath the scutellum in contrast to two in beetles. The scutellum in jewel bugs also does not have a division in the middle and thus does not 'split open' when they take flight like in beetles. The heads of jewel bugs are triangular and the antennae have three to five segments. Like all heteropterans, jewel bugs are characterized by a segmented beak-like mouthpart (known as the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

). During feeding, jewel bugs inject

proteolytic enzymes A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do t ...

in their

saliva Saliva (commonly referred as spit or drool) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which ...

into plants, digesting plant matter into a liquid form which they then suck up. The tarsus has three segments (tarsomeres). File:Calliphara exellens (Burmeister, 1834).jpg, ''

Calliphara excellens ''Calliphara excellens'' is a jewel bug in the family Scutelleridae. It is distributed in Nepal and India. Males engage in ritualistic Courtship display, walking around the female, touching his abdomen to the plant before touching the female's an ...

'' from Japan. File:Chrysocoris macrogiants A.jpg, Jewel bug in

Mumbai Mumbai ( ; ), also known as Bombay ( ; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12 ...

File:Chrysocoris macrogiants C.jpg, Jewel bug in

File:Jewel Bug-Chennai.jpg, Jewel bug spotted tucked away in the canopy at

Chennai Chennai, also known as Madras (List of renamed places in India#Tamil Nadu, its official name until 1996), is the capital city, capital and List of cities in Tamil Nadu by population, largest city of Tamil Nadu, the southernmost states and ...

File:Shield-backed bug (Graptocoris aulicus) nymph.jpg, Shield-backed bug (''Graptocoris aulicus'') nymph,

Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the ...

File:Chrysocoris, Hebbal, Bangalore, India - 20060806.jpg, alt=Chrysocoris sp. from India, perched on some leaves., ''

Chrysocoris ''Chrysocoris'' is a genus of brightly colored shield-backed bugs belonging to the family Scutelleridae, erected by Carl Wilhelm Hahn Carl Wilhelm Hahn (Lat. ''Carolus Guilielmus Hahn'', 16 December 1786 – 7 November 1835) was a German zoo ...

'' sp., an iridescent green jewel bug from

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. File:Giant jewel bug (Eucorysses grandis).jpg, alt=Eucorysses grandis from Japan, crawling up on a wall., A brilliant orange, red, and black giant jewel stink bug ''

Eucorysses grandis ''Eucorysses grandis'' is a species of shield-backed bugs belonging to the tribe Scutellerini.Biolib.cz
species ...

'', from

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. The pattern and coloration of this species can often vary from pale cream to deep red. File:ミヤコキンカメムシ Lampromicra miyakona 西表島 2018-11-24.jpg, ''

Lampromicra miyakona ''Lampromicra'' is a genus of true bugs in the family Scutelleridae. As with other genera in this family, they may be referred-to as "jewel bugs" or "metallic shield bugs". Distribution ''Lampromicra'' have been recorded in parts of Australia (Q ...

'' from Japan.

Colours

Though some species are quite drab, the most conspicuous jewel bugs are often brilliantly colored, exhibiting a wide range of iridescent metallic hues that change with the view angle. The colors are the result of a combination of factors. Some species like ''

Chrysocoris stockerus ''Chrysocoris'' is a genus of brightly colored shield-backed bugs belonging to the family Scutelleridae, erected by Carl Wilhelm Hahn in 1834. Species are recorded from South and SE Asia. Selected species The following are included in ''BioLib. ...

'' and ''

Scutellera nobilis ''Scutellera'' is the type genus of shield bugs in the subfamily Scutellerinae and tribe Scutellerini. Species are recorded from South and SE Asia. Species The following names have been included,chitin Chitin (carbon, C8hydrogen, H13oxygen, O5nitrogen, N)n ( ) is a long-chain polymer of N-Acetylglucosamine, ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cell ...

. The colors often change or become duller when the specimens are dried, due to the topmost chitinous layer becoming

opaque Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shie ...

and obscuring the colors of the bottom layer. The colors can be restored by moistening the surface with water.

Iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes. Iridescence is caused by wave interference of light in microstru ...

(or goniochromism) in jewel bugs like ''

Poecilocoris lewisi ''Poecilocoris lewisi'', known as the clown stink bug, is a species of shield bug found in eastern Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special ad ...

'' are the result of

structural coloration Structural coloration in animals, and a few plants, is the production of colour by microscopically structured surfaces fine enough to interfere with visible light instead of Biological pigment, pigments, although some structural coloration occu ...

. Instead of pigments, the colors are caused by the

interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extra ...

diffraction Diffraction is the deviation of waves from straight-line propagation without any change in their energy due to an obstacle or through an aperture. The diffracting object or aperture effectively becomes a secondary source of the Wave propagation ...

, or

scattering In physics, scattering is a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiat ...

of light by numerous tiny structures. In ''

'', multiple tiny conical protuberances around 900 nm in height and averaging at a diameter of 360 nm are scattered on the

epicuticle Arthropods are covered with a tough, resilient integument, cuticle or exoskeleton of chitin. Generally the exoskeleton will have thickened areas in which the chitin is reinforced or stiffened by materials such as minerals or hardened proteins. T ...

. These structures affect light passing through them, producing their oily-looking blue sheen (known as the

Tyndall effect The Tyndall effect is light scattering by particles in a colloid such as a very fine suspension (a sol). Also known as Tyndall scattering, it is similar to Rayleigh scattering, in that the intensity of the scattered light is inversely propor ...

Mie scattering In electromagnetism, the Mie solution to Maxwell's equations (also known as the Lorenz–Mie solution, the Lorenz–Mie–Debye solution or Mie scattering) describes the scattering of an electromagnetic plane wave by a homogeneous sphere. The sol ...

). In other species like the African shield bug ('' Calidea panaethiopica''), the dorsal

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

is dotted with tiny regularly spaced hemispherical cavities. The depressions act like Bragg mirrors. When light hits the pitted surface, it gives off multiple reflections resulting in the distinctive two tone yellow-blue iridescence. The colors and patterns on jewel bugs can vary significantly between

instar An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...

s and even within adults of a species. Jewel bugs are also known to

mimic In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simples ...

the colors, patterns, and shape of other organisms for defensive purposes. An example is the yellow-spotted black ''

Steganocerus multipunctatus ''Steganocerus multipunctatus'' Thunberg 1783, or ladybird bug, is a Sub-Saharan African member of the Hemiptera with a strong resemblance to a Ladybird. It is normally black with bright orange spots, but is quite variable in colour and may be b ...

'' which exhibits

Müllerian mimicry Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimicry, mimic each other's honest signal, honest aposematism, warning signals, to their mutuali ...

with the

tortoise beetle The Cassidinae (tortoise and leaf-mining beetles) are a subfamily of the leaf beetles, or Chrysomelidae. The antennae arise close to each other and some members have the pronotal and Elytron, elytral edges extended to the side and covering the le ...

'' Chiridopsis suffriani''.

Ecology and life cycle

All jewel bugs feed on

plants Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars f ...

(

phytophagous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet (nutrition), diet. These more broadly also encompass an ...

). The eggs are laid in compact clusters. They may be round or barrel-shaped with a lid or a cap at the top (known as the operculum). They also contain a ring of small protuberances near the cap called

micropylar {{Short pages monitor